Spatially telescoping measurements for improved characterization of ground water-surface water interactions
Spatially telescoping measurements for improved characterization of ground water-surface water interactions
复制标题
空间伸缩测量可改善地下水与地表水相互作用的表征
DOI：
10.1016/j.jhydrol.2012.04.002
复制
发表时间：
2012
影响因子：
6.4
通讯作者：
J. Welker
中科院分区：
文献类型：
--
作者：
C. Kikuchi;T. Ferré;J. Welker
用于描述地下水和地表水之间通量的测量方法正在迅速增加。然而，很少有研究探讨的方法，包括多种方法的实地调查的设计。我们建议，在空间伸缩序列进行现场测量，提高测量的灵活性和帐户嵌套的异质性，同时仍然允许简约的实验设计。我们采用这种空间伸缩的方法在研究地下水-地表水（GW-SW）的相互作用在基流条件沿着露西尔溪，位于阿拉斯加州附近的瓦西拉。流域尺度的数据，包括通道地貌指数和水文地质断面，被用来筛选潜在的显着GW-SW交换的地区。具体而言，这些数据表明，地下水的贡献越来越多，从更深的区域含水层沿着中游到下游的流。这一初步评估进行了测试，在基流条件下，包括差分流量测量和使用化学示踪剂分析的三组分混合模型的地下水贡献达到规模的估计。河段尺度的测量表明，随着化学成分向区域地下水端员的转变，沿着流的中游排放量大幅增加。最后，点测量的垂直水通量-获得使用渗透计以及基于温度的方法-被用来评估GW-SW交换的空间和时间的变化在代表性的河段。向上通量的空间变异性，估计使用河床温度映射在子河段尺度，观察到不同的河床成分和差异排放测量的地下水贡献的大小。空间伸缩方法提高了实地调查的效率。从流域尺度数据开始我们的评估，使我们能够确定GW-SW交换的位置，在代表性的现场进行计划测量，并改进我们对范围尺度和点尺度测量的解释。
The suite of measurement methods available to characterize fluxes between groundwater and surface water is rapidly growing. However, there are few studies that examine approaches to design of field investigations that include multiple methods. We propose that performing field measurements in a spatially telescoping sequence improves measurement flexibility and accounts for nested heterogeneities while still allowing for parsimonious experimental design. We applied this spatially telescoping approach in a study of ground water–surface water (GW–SW) interaction during baseflow conditions along Lucile Creek, located near Wasilla, Alaska. Catchment-scale data, including channel geomorphic indices and hydrogeologic transects, were used to screen areas of potentially significant GW–SW exchange. Specifically, these data indicated increasing groundwater contribution from a deeper regional aquifer along the middle to lower reaches of the stream. This initial assessment was tested using reach-scale estimates of groundwater contribution during baseflow conditions, including differential discharge measurements and the use of chemical tracers analyzed in a three-component mixing model. The reach-scale measurements indicated a large increase in discharge along the middle reaches of the stream accompanied by a shift in chemical composition towards a regional groundwater end member. Finally, point measurements of vertical water fluxes – obtained using seepage meters as well as temperature-based methods – were used to evaluate spatial and temporal variability of GW–SW exchange within representative reaches. The spatial variability of upward fluxes, estimated using streambed temperature mapping at the sub-reach scale, was observed to vary in relation to both streambed composition and the magnitude of groundwater contribution from differential discharge measurements. The spatially telescoping approach improved the efficiency of this field investigation. Beginning our assessment with catchment-scale data allowed us to identify locations of GW–SW exchange, plan measurements at representative field sites and improve our interpretation of reach-scale and point-scale measurements.